A primary objective is the elucidation of the structure of the adduct of N-2,3-butadienyl-N-benzylmethylamine with the mitochondrial membrane-bound, flavin-linked enzyme, monoamine oxidase (MAO). This study will serve as a prtotype for the elucidation of the mechanism of formation, kinetics, and structure, of monoamine oxidase adducts derived from inactivators with potentially reactive double bonds. The elucidation of the structure of the adduct will involve the synthesis of radioactively labelled N-2,3-butadienyl-N-benzylmethylamine, and then treatment and inactivation of purified MAO with this reagent. Enzymatic degradation of the inactivated flavoenzyme to a flavin-peptide-inhibitor complex (it is known from my previous studies that the inactivator becomes linked to the flavin) will allow characterization of the complex by chemical and spectroscopic means. A photochemical model will also be developed. We hope to clarify the inhibitory role of the allenic unit in N-2,3-butadienyl-N-benzyl-methyl-amine. To do so, derivatives of this compound will be tested to elucidate the structural requirements of allenic amine inactivation of MAO. The substituents R1, R2 and R3 attached to the allenic framework, will be systematically varied to determine the effect of substitution on the biological activity of allenic amines. The synthesis of functionalized allenes is straightforward and a number of methods are outlined in the body of this proposal. Finally, the susceptibility of flavins to cycloaddition reactions with various unsaturated species will be explored. The rationale for this exploration is based on the notion that the bis-imino functionality is a potentially rective feature of the flavin nucleus. We intend to determine the electron demands of this unit by challenging it with a judicious choice of available organic reagents. Once the electron demands for cycloaddition are defined, our strategy will be to design inactivators of MAO and other flavo-enzymes which incorporate the features necessary for irreversible inactivation.